Fix a typo in the RSA benchmark.

src/platform/vboot_reference/utils/file_keys.c

Index: src/platform/vboot_reference/utils/file_keys.c
diff --git a/src/platform/vboot_reference/utils/file_keys.c b/src/platform/vboot_reference/utils/file_keys.c
index 1aac93f98960fb01f4ec04acbc4fcc273b926c72..98e878ae4409fc802b18cfbddfb759a35fc3e332 100644
--- a/src/platform/vboot_reference/utils/file_keys.c
+++ b/src/platform/vboot_reference/utils/file_keys.c
@@ -51,7 +51,7 @@ uint8_t* BufferFromFile(const char* input_file, uint32_t* len) {
 
 RSAPublicKey* RSAPublicKeyFromFile(const char* input_file) {
   uint32_t len;
-  RSAPublicKey* key;
+  RSAPublicKey* key = NULL;
   uint8_t* buf = BufferFromFile(input_file, &len);
   if (buf)
     key = RSAPublicKeyFromBuf(buf, len);