efi_loader: use LOGC_EFI consistently

The log category should be LOGC_EFI all over the EFI sub-system.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
diff --git a/lib/efi_loader/efi_fdt.c b/lib/efi_loader/efi_fdt.c
index f882622..1ba6641 100644
--- a/lib/efi_loader/efi_fdt.c
+++ b/lib/efi_loader/efi_fdt.c
@@ -6,6 +6,8 @@
  * Written by Simon Glass <sjg@chromium.org>
  */
 
+#define LOG_CATEGORY LOGC_EFI
+
 #include <efi_loader.h>
 #include <env.h>
 #include <errno.h>