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_esrt.c b/lib/efi_loader/efi_esrt.c
index 443bd99..e235c8f 100644
--- a/lib/efi_loader/efi_esrt.c
+++ b/lib/efi_loader/efi_esrt.c
@@ -5,6 +5,8 @@
  *  Copyright (C) 2021 Arm Ltd.
  */
 
+#define LOG_CATEGORY LOGC_EFI
+
 #include <efi_loader.h>
 #include <log.h>
 #include <efi_api.h>