Bug#748322: blender: FTBFS on non-Linux

[Rebecca N. Palmer]

Package: blender
Version: 2.70-2
Tags: patch

blender 2.70 fails to build on kFreeBSD with
/«PKGBUILDDIR»/intern/guardedalloc/intern/mallocn_intern.h:66:4: error: 
#error "We don't know how to use malloc_usable_size on your platform"

It appears that this file is checking for Linux ( #if defined(__linux__) 
at line 54) when it should be checking for GNU libc ( __GLIBC__, 
https://wiki.debian.org/Debian_GNU/kFreeBSD_FAQ?highlight=%28kfreebsd%29#Q._How_do_I_detect_kfreebsd_with_preprocessor_directives_in_a_C_program.3F), 
though I have not tested this fix.