libguestfs: mark broken on musl.

Our musl-legacy-compat package should provide static inline versions of
error(3), but it's erroring out during linking:

/usr/bin/ld: ../lib/.libs/libguestfs.so: undefined reference to `error'
collect2: error: ld returned 1 exit status

srcpkgs/libguestfs/template

@@ -30,6 +30,9 @@ conf_files="etc/libguestfs-tools.conf
 
 nocross=yes
 archs="i686* x86_64* ppc64le*"
+if [ "$XBPS_TARGET_LIBC" = musl ]; then
+	broken="https://build.voidlinux.org/builders/x86_64-musl_builder/builds/35666/steps/shell_3/logs/stdio"
+fi
 
 build_options="ruby python go php lua fuse"
 build_options_default="ruby fuse"