doc/doxygen/doxygen_filter.sh.in: only remove lines which START with //

doc/doxygen/doxygen_filter.sh.in

@@ -5,6 +5,6 @@ if [ "$(basename $1)" == "starpufft.h" ] ; then
 else
     # the macro STARPU_DEPRECATED needs to be removed as it is not properly processed by doxygen
     # lines starting with // in the doxygen input files are considered as comments to be removed
-    sed -e 's/STARPU_DEPRECATED//' $1 | sed 's/\/\/.*//'
+    sed -e 's/STARPU_DEPRECATED//' $1 | sed 's/^\/\/.*//'
 fi