unwind: give all exported functions "unwind_" prefix

* unwind.c (init_unwind_addr_space): Rename to unwind_init.
(init_libunwind_ui): Rename to unwind_tcb_init.
(free_libunwind_ui): Rename to unwind_tcb_fin.
(delete_mmap_cache): Rename to unwind_cache_invalidate.
(print_stacktrace): Rename to unwind_print_stacktrace.
* defs.h: Update prototypes.
* mem.c: All callers updated.
* process.c: Likewise.
* strace.c: Likewise.
* syscall.c: Likewise.

Signed-off-by: Masatake YAMATO <yamato@redhat.com>
diff --git a/defs.h b/defs.h
index 97deab3..f642d65 100644
--- a/defs.h
+++ b/defs.h
@@ -732,11 +732,11 @@
 extern void tv_div(struct timeval *, const struct timeval *, int);
 
 #ifdef USE_LIBUNWIND
-extern void init_unwind_addr_space(void);
-extern void init_libunwind_ui(struct tcb *tcp);
-extern void free_libunwind_ui(struct tcb *tcp);
-extern void delete_mmap_cache(struct tcb* tcp);
-extern void print_stacktrace(struct tcb* tcp);
+extern void unwind_init(void);
+extern void unwind_tcb_init(struct tcb *tcp);
+extern void unwind_tcb_fin(struct tcb *tcp);
+extern void unwind_cache_invalidate(struct tcb* tcp);
+extern void unwind_print_stacktrace(struct tcb* tcp);
 #endif
 
 /* Strace log generation machinery.