package/exfat-utils: fix compilation error with musl

exfat-utils build would not build on Linux unless __GLIBC__ was defined.
Patch added to use more relaxed __linux__ instead.

See http://autobuild.buildroot.net/results/c60/c60d0f9a93c90d41c3c86c78b0a0

Signed-off-by: Brendan Heading <brendanheading@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/exfat-utils/0001-fix-compiling-with-non-glibc-libcs.patch

@@ -0,0 +1,23 @@
+[PATCH] fix compilation when libc does not define __GLIBC__
+
+libexfat would only compile on Linux with __GLIBC__ defined. Changed
+to use __linux__ which likely better fits the original intent.
+
+Signed-off-by: Brendan Heading <brendanheading@gmail.com>
+---
+ platform.h |    2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+Index: libexfat/libexfat/platform.h
+===================================================================
+--- libexfat/libexfat/platform.h	(revision 422)
++++ libexfat/libexfat/platform.h	(working copy)
+@@ -24,7 +24,7 @@
+ #ifndef PLATFORM_H_INCLUDED
+ #define PLATFORM_H_INCLUDED
+ 
+-#if defined(__GLIBC__)
++#if defined(__linux__)
+ 
+ #include <endian.h>
+ #include <byteswap.h>