common: move safe_copy_string_from_guest() to lib/

This function is unreachable on x86 when XSM_FLASK=n, and it is another
good candidate to put in an archive.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>

xen/common/Makefile

@@ -16,7 +16,6 @@ obj-y += event_2l.o
 obj-y += event_channel.o
 obj-$(CONFIG_EVTCHN_FIFO) += event_fifo.o
 obj-$(CONFIG_GRANT_TABLE) += grant_table.o
-obj-y += guestcopy.o
 obj-y += gzip/
 obj-$(CONFIG_HYPFS) += hypfs.o
 obj-$(CONFIG_IOREQ_SERVER) += ioreq.o

xen/lib/Makefile

@@ -6,6 +6,7 @@ lib-y += find-next-bit.o
 lib-y += generic-ffsl.o
 lib-y += generic-flsl.o
 lib-y += generic-hweightl.o
+lib-y += guest-strcpy.o
 lib-y += list-sort.o
 lib-y += memchr.o
 lib-y += memchr_inv.o