zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c

zlib: move EXPORT_SYMBOL() and MODULE_LICENSE() out of dfltcc_syms.c

In commit 11fb479ff5d9 ("zlib: export S390 symbols for zlib modules"), I
added EXPORT_SYMBOL()s to dfltcc_inflate.c but then Mikhail said that
these should probably be in dfltcc_syms.c with the other
EXPORT_SYMBOL()s.

However, that is contrary to the current kernel style, which places
EXPORT_SYMBOL() immediately after the function that it applies to, so
move all EXPORT_SYMBOL()s to their respective function locations and
drop the dfltcc_syms.c file.  Also move MODULE_LICENSE() from the
deleted file to dfltcc.c.

[rdunlap@infradead.org: remove dfltcc_syms.o from Makefile]
Link: https://lkml.kernel.org/r/20201227171837.15492-1-rdunlap@infradead.org
Link: https://lkml.kernel.org/r/20201219052530.28461-1-rdunlap@infradead.org
Fixes: 11fb479ff5d9 ("zlib: export S390 symbols for zlib modules")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Acked-by: Ilya Leoshkevich <iii@linux.ibm.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Zaslonko Mikhail <zaslonko@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>