examples: make: fix LOGGER=rtt

CMake builds worked, but the variables were brokenly updated for make.

Fixes: a64e3eb update board_test always output on uart
Signed-off-by: Karl Palsson <[email protected]>

Author: karlp

examples/build_system/make/make.mk

@@ -134,8 +134,8 @@ endif
 ifeq ($(LOGGER),rtt)
   CFLAGS += -DLOGGER_RTT
   #CFLAGS += -DSEGGER_RTT_MODE_DEFAULT=SEGGER_RTT_MODE_BLOCK_IF_FIFO_FULL
-  INC   += $(TOP)/$(lib/SEGGER_RTT)/RTT
-  SRC_C += $(lib/SEGGER_RTT)/RTT/SEGGER_RTT.c
+  INC   += $(TOP)/lib/SEGGER_RTT/RTT
+  SRC_C += lib/SEGGER_RTT/RTT/SEGGER_RTT.c
 endif
 ifeq ($(LOGGER),swo)
   CFLAGS += -DLOGGER_SWO