umockdev-wrapper: Exec program instead of running it as a child

This avoids keeping the shell process around and makes killing the subprogram
from outside work properly.

NEWS

@@ -1,3 +1,8 @@
+0.2.1 (UNRELEASED)
+------------------
+- umockdev-wrapper: Use exec to avoid keeping the shell process around and make
+  killing the subprogram from outside work properly.
+
 0.2 (2013-02-20)
 ----------------
 Compatibility break: This does not work any more with recorded ioctl files from

src/umockdev-wrapper

@@ -1,5 +1,5 @@
 #!/bin/sh
 # Wrapper program to preload the libumockdev library, so that test programs can
 # set $UMOCKDEV_DIR for redirecting sysfs and other queries to a test bed.
-env LD_PRELOAD=libumockdev-preload.so.0:$LD_PRELOAD "$@"
+exec env LD_PRELOAD=libumockdev-preload.so.0:$LD_PRELOAD "$@"