kernel-doc: small kernel-doc optimization

Get the kernel version string only once from the environment, thus slightly
speeding up kernel-doc.

Signed-off-by: Borislav Petkov <bbpetkov@yahoo.de>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/kernel-doc

@@ -337,6 +337,7 @@ sub get_kernel_version() {
     }
     return $version;
 }
+my $kernelversion = get_kernel_version();
 
 # generate a sequence of code that will splice in highlighting information
 # using the s// operator.
@@ -610,7 +611,7 @@ sub output_function_xml(%) {
     print "<refmeta>\n";
     print " <refentrytitle><phrase>".$args{'function'}."</phrase></refentrytitle>\n";
     print " <manvolnum>9</manvolnum>\n";
-    print " <refmiscinfo class=\"version\">" . get_kernel_version() . "</refmiscinfo>\n";
+    print " <refmiscinfo class=\"version\">" . $kernelversion . "</refmiscinfo>\n";
     print "</refmeta>\n";
     print "<refnamediv>\n";
     print " <refname>".$args{'function'}."</refname>\n";
@@ -687,7 +688,7 @@ sub output_struct_xml(%) {
     print "<refmeta>\n";
     print " <refentrytitle><phrase>".$args{'type'}." ".$args{'struct'}."</phrase></refentrytitle>\n";
     print " <manvolnum>9</manvolnum>\n";
-    print " <refmiscinfo class=\"version\">" . get_kernel_version() . "</refmiscinfo>\n";
+    print " <refmiscinfo class=\"version\">" . $kernelversion . "</refmiscinfo>\n";
     print "</refmeta>\n";
     print "<refnamediv>\n";
     print " <refname>".$args{'type'}." ".$args{'struct'}."</refname>\n";
@@ -772,7 +773,7 @@ sub output_enum_xml(%) {
     print "<refmeta>\n";
     print " <refentrytitle><phrase>enum ".$args{'enum'}."</phrase></refentrytitle>\n";
     print " <manvolnum>9</manvolnum>\n";
-    print " <refmiscinfo class=\"version\">" . get_kernel_version() . "</refmiscinfo>\n";
+    print " <refmiscinfo class=\"version\">" . $kernelversion . "</refmiscinfo>\n";
     print "</refmeta>\n";
     print "<refnamediv>\n";
     print " <refname>enum ".$args{'enum'}."</refname>\n";