[binutils-gdb] Use scoped_restore in a couple of interp-related places

[sergiodj+buildbot@sergiodj.net]

*** TEST RESULTS FOR COMMIT 753ff9bd837e2ba183e3ff789847a81221561392 ***

Author: Tom Tromey <tom@tromey.com>
Branch: master
Commit: 753ff9bd837e2ba183e3ff789847a81221561392

Use scoped_restore in a couple of interp-related places

While looking through the "interp" code I found a couple of spots that
could use scoped_restore.

ChangeLog
2018-05-25  Tom Tromey  <tom@tromey.com>

	* cli/cli-interp.c (safe_execute_command): Use scoped_restore.
	* interps.c (interp_exec): Use scoped_restore.