efi_selftest: remove redundant function efi_st_memcmp()

Function memcmp() is available in efi_freestanding.c. So we do not remove a
further implementation.

Replace all usages of efi_st_memcmp() by memcmp().

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/lib/efi_selftest/efi_selftest_manageprotocols.c b/lib/efi_selftest/efi_selftest_manageprotocols.c
index 0ff35ce..8edb1e4 100644
--- a/lib/efi_selftest/efi_selftest_manageprotocols.c
+++ b/lib/efi_selftest/efi_selftest_manageprotocols.c
@@ -332,13 +332,13 @@
 		efi_st_error("Failed to get protocols per handle\n");
 		return EFI_ST_FAILURE;
 	}
-	if (efi_st_memcmp(prot_buffer[0], &guid1, 16) &&
-	    efi_st_memcmp(prot_buffer[1], &guid1, 16)) {
+	if (memcmp(prot_buffer[0], &guid1, 16) &&
+	    memcmp(prot_buffer[1], &guid1, 16)) {
 		efi_st_error("Failed to get protocols per handle\n");
 		return EFI_ST_FAILURE;
 	}
-	if (efi_st_memcmp(prot_buffer[0], &guid3, 16) &&
-	    efi_st_memcmp(prot_buffer[1], &guid3, 16)) {
+	if (memcmp(prot_buffer[0], &guid3, 16) &&
+	    memcmp(prot_buffer[1], &guid3, 16)) {
 		efi_st_error("Failed to get protocols per handle\n");
 		return EFI_ST_FAILURE;
 	}