bsd-user: Remove last_brk

This variable is unused.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

bsd-user/mmap.c

@@ -214,8 +214,6 @@ static int mmap_frag(abi_ulong real_start,
 #endif
 abi_ulong mmap_next_start = TASK_UNMAPPED_BASE;
 
-unsigned long last_brk;
-
 /*
  * Subroutine of mmap_find_vma, used when we have pre-allocated a chunk of guest
  * address space.

bsd-user/qemu.h

@@ -232,7 +232,6 @@ abi_long target_mremap(abi_ulong old_addr, abi_ulong old_size,
                        abi_ulong new_size, unsigned long flags,
                        abi_ulong new_addr);
 int target_msync(abi_ulong start, abi_ulong len, int flags);
-extern unsigned long last_brk;
 extern abi_ulong mmap_next_start;
 abi_ulong mmap_find_vma(abi_ulong start, abi_ulong size);
 void TSA_NO_TSA mmap_fork_start(void);