Words. Use them!

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/doxygen/mbedtls.doxyfile b/doxygen/mbedtls.doxyfile
index aa8eb41..c33c7e3 100644
--- a/doxygen/mbedtls.doxyfile
+++ b/doxygen/mbedtls.doxyfile
@@ -28,7 +28,7 @@
 MAX_DOT_GRAPH_DEPTH    = 1000
 DOT_TRANSPARENT        = YES
 
-# We mostly \retval declarations to document which error codes a function
+# We mostly use \retval declarations to document which error codes a function
 # can return. The reader can follow the hyperlink to the definition of the
 # constant to get the generic documentation of that error code. If we don't
 # have anything to say about the specific error code for the specific