libkern: remove bcopy

Unused since ba96f37758 ("Use __builtin for various mem* and b* (e.g. bzero)
routines.")

File name remains to reduce churn.

Sponsored by:	Rubicon Communications, LLC ("Netgate")

sys/libkern/bcopy.c

@@ -52,7 +52,6 @@ __FBSDID("$FreeBSD$");
 
 #undef memcpy
 #undef memmove
-#undef bcopy
 
 /*
  * sizeof(word) MUST BE A POWER OF TWO
@@ -147,10 +146,3 @@ memcpy(void *dst0, const void *src0, size_t length)
 }
 
 __strong_reference(memcpy, memmove);
-
-void
-(bcopy)(const void *src0, void *dst0, size_t length)
-{
-
-	memcpy(dst0, src0, length);
-}