lib/zlib: remove redundation assignement of avail_in dfltcc_gdht()

cppcheck reports
lib/zlib_dfltcc/dfltcc_deflate.c:65:21: warning: Redundant assignment of 'avail_in' to itself. [selfAssignment]
size_t avail_in = avail_in = strm->avail_in;

Only setting avail_in once is needed.

Link: https://lkml.kernel.org/r/[e-mail]
Fixes: aa5b395b69b6 ("lib/zlib: add s390 hardware support for kernel zlib_deflate")
Signed-off-by: Tom Rix <[e-mail]>
Acked-by: Ilya Leoshkevich <[e-mail]>
Acked-by: Mikhail Zaslonko <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>

lib/zlib_dfltcc/dfltcc_deflate.c

···
 {
     deflate_state *state = (deflate_state *)strm->state;
     struct dfltcc_param_v0 *param = &GET_DFLTCC_STATE(state)->param;
-    size_t avail_in = avail_in = strm->avail_in;
+    size_t avail_in = strm->avail_in;
 
     dfltcc(DFLTCC_GDHT,
            param, NULL, NULL,