[PATCH] Do not build manual in source directory

[Alfred M. Szmidt]

   2012-04-23  Andreas Jaeger  <aj@suse.de>

	   [BZ #13570]

Now this is confusing, what does this have to do with "Controlling
gmon.out file creation in HPC environment"
(http://sourceware.org/bugzilla/show_bug.cgi?id=13570)?