Makefile: Use printf instead of echo -n

On MacOS `echo -n` is not working.

Change-Id: I96bb6c60e74133bbc86d5069cb076ee43f4bca83
Signed-off-by: Thomas Heijligen <[email protected]>
Reviewed-on: https://review.coreboot.org/c/flashrom/+/74522
Reviewed-by: Paul Menzel <[email protected]>
Reviewed-by: Anastasia Klimchuk <[email protected]>
Tested-by: build bot (Jenkins) <[email protected]>

Makefile

@@ -965,7 +965,7 @@ endif
 
 config:
  @echo Building flashrom version $(VERSION)
- @echo -n "C compiler found: "
+ @printf "C compiler found: "
  @if [ $(CC_WORKING) = yes ]; \
  then $(CC) --version 2>/dev/null | head -1; \
  else echo no; echo Aborting.; exit 1; fi