Added missing LZMA_API to the C versions of the CRC functions.

The x86 assembler versions were already OK.

src/liblzma/check/crc32.c

@@ -18,7 +18,7 @@
 // If you make any changes, do some bench marking! Seemingly unrelated
 // changes can very easily ruin the performance (and very probably is
 // very compiler dependent).
-extern uint32_t
+extern LZMA_API uint32_t
 lzma_crc32(const uint8_t *buf, size_t size, uint32_t crc)
 {
 	crc = ~crc;

src/liblzma/check/crc64.c

@@ -23,7 +23,7 @@
 
 
 // See comments in crc32.c.
-extern uint64_t
+extern LZMA_API uint64_t
 lzma_crc64(const uint8_t *buf, size_t size, uint64_t crc)
 {
 	crc = ~crc;