efi_loader: use constants in efi_allocate_pages()

Using the existing predefined constants is less error prone and
makes the code easier to read.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index ff0edf3..1e413d0 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -292,7 +292,7 @@
 	uint64_t addr;
 
 	switch (type) {
-	case 0:
+	case EFI_ALLOCATE_ANY_PAGES:
 		/* Any page */
 		addr = efi_find_free_memory(len, gd->start_addr_sp);
 		if (!addr) {
@@ -300,7 +300,7 @@
 			break;
 		}
 		break;
-	case 1:
+	case EFI_ALLOCATE_MAX_ADDRESS:
 		/* Max address */
 		addr = efi_find_free_memory(len, *memory);
 		if (!addr) {
@@ -308,7 +308,7 @@
 			break;
 		}
 		break;
-	case 2:
+	case EFI_ALLOCATE_ADDRESS:
 		/* Exact address, reserve it. The addr is already in *memory. */
 		addr = *memory;
 		break;