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_acpi.c b/lib/efi_loader/efi_acpi.c
index ff305a6..4422b31 100644
--- a/lib/efi_loader/efi_acpi.c
+++ b/lib/efi_loader/efi_acpi.c
@@ -5,6 +5,8 @@
  *  Copyright (C) 2018, Bin Meng <bmeng.cn@gmail.com>
  */
 
+#define LOG_CATEGORY LOGC_EFI
+
 #include <efi_loader.h>
 #include <log.h>
 #include <mapmem.h>