tools/lib/lockdep: Fix link creation warning

This warning triggers if the .so library has already been linked:

triton:~/tip/tools/lib/lockdep> make
CC common.o
CC lockdep.o
CC rbtree.o
LD liblockdep-in.o
LD liblockdep.a
ln: failed to create symbolic link ‘liblockdep.so’: File exists
LD liblockdep.so.4.5.0-rc6

Overwrite the link.

Cc: Alfredo Alvarez Fernandez <[e-mail]>
Cc: Andrew Morton <[e-mail]>
Cc: Linus Torvalds <[e-mail]>
Cc: Paul E. McKenney <[e-mail]>
Cc: Peter Zijlstra <[e-mail]>
Cc: Sasha Levin <[e-mail]>
Cc: Thomas Gleixner <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ingo Molnar <[e-mail]>

tools/lib/lockdep/Makefile

···
 
 do_compile_shared_library =			\
 	($(print_shared_lib_compile)		\
-	$(CC) --shared $^ -o $@ -lpthread -ldl -Wl,-soname='"$@"';$(shell ln -s $@ liblockdep.so))
+	$(CC) --shared $^ -o $@ -lpthread -ldl -Wl,-soname='"$@"';$(shell ln -sf $@ liblockdep.so))
 
 do_build_static_lib =				\
 	($(print_static_lib_build)		\