LD      init/built-in.o
  LD      .tmp_vmlinux1
fs/built-in.o(.text+0xac537): In function `gzip1_alloc':
: undefined reference to `zlib_deflate_workspacesize'
fs/built-in.o(.text+0xac54a): In function `gzip1_alloc':
: undefined reference to `zlib_deflate_workspacesize'
fs/built-in.o(.text+0xac778): In function `gzip1_compress':
: undefined reference to `zlib_deflateInit2_'
fs/built-in.o(.text+0xac78c): In function `gzip1_compress':
: undefined reference to `zlib_deflateReset'
fs/built-in.o(.text+0xac7c8): In function `gzip1_compress':
: undefined reference to `zlib_deflate'
make: *** [.tmp_vmlinux1] Error 1