perf/unwind: include errno.h unconditionally

EINVAL is used in other branches as well. Without errno.h, it ends up
undefined and the build fails. This happens with 32-bit ROSA kernels,
for example.

kernel.spec

@@ -200,6 +200,9 @@ Patch108:	ata-prefer-ata-drivers-over-ide-drivers-when-both-are-built.patch
 # AUFS from http://aufs.sourceforge.net/
 Patch109:	fs-aufs4.patch
 
+# Fix building of perf on 32-bit systems
+Patch110:	perf-unwind-include-errno_h.patch
+
 # https://bugs.freedesktop.org/show_bug.cgi?id=97822
 # http://bugs.rosalinux.ru/show_bug.cgi?id=7533
 Patch200:	i915_hack_bug_97822.patch

perf-unwind-include-errno_h.patch

@@ -0,0 +1,19 @@
+perf/unwind: include errno.h unconditionally
+
+EINVAL is used in other branches as well. Without errno.h, it ends up
+undefined and the build fails. This happens with 32-bit ROSA kernels, for
+example.
+
+diff --git a/tools/perf/arch/x86/util/unwind-libunwind.c b/tools/perf/arch/x86/util/unwind-libunwind.c
+index 4f16661cbdbb..597588c8c7e6 100644
+--- a/tools/perf/arch/x86/util/unwind-libunwind.c
++++ b/tools/perf/arch/x86/util/unwind-libunwind.c
+@@ -1,6 +1,7 @@
+ 
++#include <errno.h> /* for EINVAL */
++
+ #ifndef REMOTE_UNWIND_LIBUNWIND
+-#include <errno.h>
+ #include <libunwind.h>
+ #include "perf_regs.h"
+ #include "../../util/unwind.h"