efi_loader: Move to normal debug infrastructure

We introduced special "DEBUG_EFI" defines when the efi loader
support was new. After giving it a bit of thought, turns out
we really didn't have to - the normal #define DEBUG infrastructure
works well enough for efi loader as well.

So this patch switches to the common debug() and #define DEBUG
way of printing debug information.

Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index 15a1b90..be6f5e8 100644
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -6,8 +6,6 @@
  *  SPDX-License-Identifier:     GPL-2.0+
  */
 
-/* #define DEBUG_EFI */
-
 #include <common.h>
 #include <efi_loader.h>
 #include <malloc.h>
@@ -76,9 +74,7 @@
 
 static efi_status_t efi_unsupported(const char *funcname)
 {
-#ifdef DEBUG_EFI
-	printf("EFI: App called into unimplemented function %s\n", funcname);
-#endif
+	debug("EFI: App called into unimplemented function %s\n", funcname);
 	return EFI_EXIT(EFI_UNSUPPORTED);
 }