lint: fix unusedVariable warnings

SQUASH ME: into unusedVariable (annotated)

SQUASH ME: into unusedVariable (II)

SQUASH ME: into unreadVariable (II)

cpu/cc430/cc110x_cc430.c

@@ -119,6 +119,8 @@ void cc110x_write_reg(uint8_t addr, uint8_t value)
 
     while (!(RFDINIFG & RF1AIFCTL1));
 
+    /* cppcheck: need to force a read to RF1ADOUTB to trigger reset */
+    /* cppcheck-suppress unreadVariable */
     i = RF1ADOUTB;                            /* Reset RFDOUTIFG flag which contains status byte */
 
     restoreIRQ(int_state);
@@ -213,6 +215,8 @@ uint8_t cc110x_writeburst_reg(uint8_t addr, char *buffer, uint8_t count)
         while (!(RFDINIFG & RF1AIFCTL1));        /* Wait for TX to finish */
     }
 
+    /* cppcheck: need to force a read to RF1ADOUTB to trigger reset */
+    /* cppcheck-suppress unreadVariable */
     i = RF1ADOUTB;                            /* Reset RFDOUTIFG flag which contains status byte */
 
     restoreIRQ(int_state);

cpu/lpc1768/startup.c

@@ -190,7 +190,7 @@ void (* const g_pfnVectors[])(void) =
 *******************************************************************************/
 void Reset_Handler(void)
 {
-    unsigned long *pulSrc, *pulDest;
+    unsigned long *pulDest;
 
     /*
      * This used for cleaning AHBRAM0 section
@@ -218,7 +218,7 @@ void Reset_Handler(void)
      * Copy the data segment initializers from flash to SRAM in ROM mode
      */
 #if (__RAM_MODE__==0)
-    pulSrc = &__sidata;
+    unsigned long *pulSrc = &__sidata;
     for(pulDest = &__data_start__; pulDest < &__data_end__; )
     {
         *(pulDest++) = *(pulSrc++);

sys/crypto/twofish.c

@@ -523,15 +523,24 @@ static int twofish_set_key(twofish_context_t *ctx, uint8_t *key, uint8_t keylen)
     int i, j, k;
 
     /* Temporaries for CALC_K. */
+    /* cppcheck: used in macros in sys/include/crypto/twofish.h that cppcheck
+     * doesn't understand
+     */
+    /* cppcheck-suppress unusedVariable */
     uint32_t x, y;
 
     /* The S vector used to key the S-boxes, split up into individual bytes.
      * 128-bit keys use only sa through sh; 256-bit use all of them. */
     uint8_t sa = 0, sb = 0, sc = 0, sd = 0, se = 0, sf = 0, sg = 0, sh = 0;
+    /* cppcheck: moving this may introduce timing vulnerability */
     /* cppcheck-suppress variableScope */
     uint8_t si = 0, sj = 0, sk = 0, sl = 0, sm = 0, sn = 0, so = 0, sp = 0;
 
     /* Temporary for CALC_S. */
+    /* cppcheck: used in macros in sys/include/crypto/twofish.h that cppcheck
+     * doesn't understand
+     */
+    /* cppcheck-suppress unusedVariable */
     uint8_t tmp;
 
     /* Check key length. */
@@ -674,6 +683,10 @@ int twofish_encrypt(cipher_context_t *context, uint8_t *in, uint8_t *out)
     uint32_t a, b, c, d;
 
     /* Temporaries used by the round function. */
+    /* cppcheck: used in macros in sys/include/crypto/twofish.h that cppcheck
+     * doesn't understand
+     */
+    /* cppcheck-suppress unusedVariable */
     uint32_t x, y;
 
     /* Input whitening and packing. */
@@ -727,6 +740,10 @@ int twofish_decrypt(cipher_context_t *context, uint8_t *in, uint8_t *out)
     uint32_t a, b, c, d;
 
     /* Temporaries used by the round function. */
+    /* cppcheck: used in macros in sys/include/crypto/twofish.h that cppcheck
+     * doesn't understand
+     */
+    /* cppcheck-suppress unusedVariable */
     uint32_t x, y;
 
     /* Input whitening and packing. */