Remove a homebrew mmap64.

This should have been fixed in bionic, and now has been.

Change-Id: Ib9b21771ed7fbb6b4082b52d0b590f2867f344d4

fastbootd/commands/partitions.c

@@ -48,8 +48,6 @@
 #include "utils.h"
 #include "protocol.h"
 
-#define MMAP2_SHIFT 12
-
 #define BLKRRPART  _IO(0x12,95) /* re-read partition table */
 #define BLKSSZGET  _IO(0x12,104)
 
@@ -70,13 +68,6 @@ static void GPT_entry_clear(struct GPT_entry_raw *entry)
     memset(entry, 0, sizeof(*entry));
 }
 
-extern void*  __mmap2(void *, size_t, int, int, int, off_t);
-
-static inline void *mmap64(void *addr, size_t length, int prot,
-                           int flags, int fd, uint64_t offset) {
-    return __mmap2(addr, length, prot, flags, fd, offset >> MMAP2_SHIFT);
-}
-
 /*
  * returns mapped location to choosen area
  * mapped_ptr is pointer to whole area mapped (it can be bigger then requested)