apply-patches: catch unexpected failure

As reported by Sébastien Szymanski [1], the apply-patches script
doesn't stop if a tar command can't extract an archive.

Use "set -e" to exit immediately if a command return an error.

[1] http://patchwork.ozlabs.org/patch/626196

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Cc: Sébastien Szymanski <sebastien.szymanski@armadeus.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

support/scripts/apply-patches.sh

@@ -31,6 +31,9 @@
 # applied. The list of the patches applied is stored in '.applied_patches_list'
 # file in the build directory.
 
+# We want to catch any unexpected failure, and exit immediately.
+set -e
+
 silent=
 if [ "$1" = "-s" ] ; then
     # add option to be used by the patch tool