Option processing fix: should match '-F' exactly, instead.

llvm-svn: 156509
diff --git a/lldb/test/redo.py b/lldb/test/redo.py
index f8b69fe..7e798a5 100755
--- a/lldb/test/redo.py
+++ b/lldb/test/redo.py
@@ -132,7 +132,7 @@
             # End of option processing.
             break
 
-        if sys.argv[index].startswith('-F'):
+        if sys.argv[index] == '-F':
             # Increment by 1 to fetch the filename component spec.
             index += 1
             if index >= len(sys.argv) or sys.argv[index].startswith('-'):