opkg: Protect add-exclude.patch from malloc failure
In the code added by add-exclude.patch, the return values of malloc and realloc
were not checked before being dereferenced.
In opkg we can use xmalloc and xrealloc instead of malloc and realloc. These
functions terminate the program instead of returning NULL if memory allocation
fails.
Signed-off-by: Paul Barker <paul@paulbarker.me.uk> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
