[Beignet] [PATCH v2] GBE: Don't read past end of printf format string

[Rebecca N. Palmer]

When p==end (the null terminator byte), don't try to read p+1
(outside the string, so might be an invalid address or a '%' from
a different object).

Signed-off-by: Rebecca Palmer <rebecca_palmer at zoho.com>

diff --git a/backend/src/llvm/llvm_printf_parser.cpp b/backend/src/llvm/llvm_printf_parser.cpp
index bdaed8a..f427107 100644
--- a/backend/src/llvm/llvm_printf_parser.cpp
+++ b/backend/src/llvm/llvm_printf_parser.cpp
@@ -229,7 +229,7 @@ again:
         printf("string end with %%\n");
         goto error;
       }
-      if (*(p + 1) == '%') { // %%
+      if (p + 1 < end && *(p + 1) == '%') { // %%
         p += 2;
         goto again;
       }