SPI: avoid using malloc() by default

Author: facchinm

libraries/SPI/src/SPI.cpp

@@ -88,7 +88,7 @@ void SPIClass::usingInterrupt(int interruptNumber)
     interruptMode = SPI_IMODE_GLOBAL;
   else
   {
-    #ifdef USE_MALLOC_FOR_IRQ_MAP
+    #if USE_MALLOC_FOR_IRQ_MAP
       if (irqMap == NULL) {
         irqMap = (uint8_t*)malloc(EXTERNAL_NUM_INTERRUPTS);
       }
@@ -119,7 +119,7 @@ void SPIClass::notUsingInterrupt(int interruptNumber)
 
   if (interruptMask_lo == 0 && interruptMask_hi == 0) {
     interruptMode = SPI_IMODE_NONE;
-    #ifdef USE_MALLOC_FOR_IRQ_MAP
+    #if USE_MALLOC_FOR_IRQ_MAP
       free(irqMap);
       irqMap = NULL;
     #endif

libraries/SPI/src/SPI.h

@@ -23,7 +23,7 @@
 #include <Arduino.h>
 
 #ifndef USE_MALLOC_FOR_IRQ_MAP
-#define USE_MALLOC_FOR_IRQ_MAP  1
+#define USE_MALLOC_FOR_IRQ_MAP  0
 #endif
 
 // SPI_HAS_TRANSACTION means SPI has