*-symbol-check: use correct nm path when cross-compiling

Inspired-by: a similar patch for libdrm by Heiko Becker
Signed-off-by: Eric Engestrom <eric.engestrom@imgtec.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>

meson.build

@@ -1256,6 +1256,9 @@ endif
 
 pkg = import('pkgconfig')
 
+env_test = environment()
+env_test.set('NM', find_program('nm').path())
+
 subdir('include')
 subdir('bin')
 subdir('src')