Merge pull request #65 from adafruit/fix-warnings

Fix a couple of warnings

Author: hathach

src/Adafruit_MCPSRAM.cpp

@@ -229,6 +229,7 @@ void Adafruit_MCPSRAM::read(uint16_t addr, uint8_t *buf, uint16_t num,
     if (hwSPI) {
       buf[i] = _spi->transfer(0x00);
     } else {
+      buf[i] = 0;
       for (uint8_t bit = 0x80; bit; bit >>= 1) {
 #ifdef HAVE_PORTREG
         *clkport &= ~clkpinmask;

src/panels/ThinkInk_420_Tricolor_Z21.h

@@ -16,6 +16,7 @@ class ThinkInk_420_Tricolor_Z21 : public Adafruit_UC8276 {
       : Adafruit_UC8276(300, 400, DC, RST, CS, SRCS, BUSY, spi){};
 
   void begin(thinkinkmode_t mode = THINKINK_TRICOLOR) {
+    (void)mode;
     Adafruit_EPD::begin(true);
     setBlackBuffer(0, true);
     setColorBuffer(1, false);