Buildroot puts nlist.h into sysroot/usr/include,
which is in the default include path.

Signed-off-by: Alex Suykov <alex.suykov@gmail.com>

--- a/ext/DynaLoader/hints/linux.pl
+++ b/ext/DynaLoader/hints/linux.pl
@@ -1,5 +1 @@
-# XXX Configure test needed.
-# Some Linux releases like to hide their <nlist.h>
-$self->{CCFLAGS} = $Config{ccflags} . ' -I/usr/include/libelf'
-	if -f "/usr/include/libelf/nlist.h";
 1;