docs: escape html special char

Signed-off-by: Brian Paul <brianp@vmware.com>
diff --git a/docs/perf.html b/docs/perf.html
index ec400c6..82e6b59 100644
--- a/docs/perf.html
+++ b/docs/perf.html
@@ -52,7 +52,7 @@
          GL_COLOR_MATERIAL is disabled
          No spot lights are used (all GL_SPOT_CUTOFFs are 180.0)
          No local lights are used (all position W's are 0.0)
-         All material and light coefficients are >= zero
+         All material and light coefficients are &gt;= zero
 <li> XFree86 users:  if you want to use 24-bit color try starting your
       X server in 32-bit per pixel mode for better performance.  That is,
       start your X server with