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

In commit 11fb479ff5 ("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: 11fb479ff5 ("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>

lib/zlib_dfltcc/dfltcc_deflate.c

@@ -4,6 +4,7 @@
 #include "dfltcc_util.h"
 #include "dfltcc.h"
 #include <asm/setup.h>
+#include <linux/export.h>
 #include <linux/zutil.h>
 
 /*
@@ -34,6 +35,7 @@ int dfltcc_can_deflate(
 
     return 1;
 }
+EXPORT_SYMBOL(dfltcc_can_deflate);
 
 static void dfltcc_gdht(
     z_streamp strm
@@ -277,3 +279,4 @@ again:
         goto again; /* deflate() must use all input or all output */
     return 1;
 }
+EXPORT_SYMBOL(dfltcc_deflate);