Fix a typo

Tools/c-analyzer/c_parser/preprocessor/gcc.py

@@ -149,7 +149,7 @@ def _iter_top_include_lines(lines, topfile, cwd,
                             raw):
     partial = 0  # depth
     files = [topfile]
-    # We start at 1 in case there are source lines (including blank onces)
+    # We start at 1 in case there are source lines (including blank ones)
     # before the first marker line.  Also, we already verified in
     # _parse_marker_line() that the preprocessor reported lno as 1.
     lno = 1