efi_loader: macro efi_size_in_pages()

When allocating EFI memory pages the size in bytes has to be converted to
pages.

Provide a macro efi_size_in_pages() for this conversion.
Use it in the EFI subsystem and correct related comments.

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 307e6f7..5359118 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -397,7 +397,7 @@
 void *efi_alloc(uint64_t len, int memory_type)
 {
 	uint64_t ret = 0;
-	uint64_t pages = (len + EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
+	uint64_t pages = efi_size_in_pages(len);
 	efi_status_t r;
 
 	r = efi_allocate_pages(EFI_ALLOCATE_ANY_PAGES, memory_type, pages,
@@ -440,8 +440,8 @@
 {
 	efi_status_t r;
 	struct efi_pool_allocation *alloc;
-	u64 num_pages = (size + sizeof(struct efi_pool_allocation) +
-			 EFI_PAGE_MASK) >> EFI_PAGE_SHIFT;
+	u64 num_pages = efi_size_in_pages(size +
+					  sizeof(struct efi_pool_allocation));
 
 	if (!buffer)
 		return EFI_INVALID_PARAMETER;