Don't define fd for platforms that do not use it, as some may not declare fileno() properly

crypto/bio/bss_file.c

@@ -214,13 +214,14 @@ static long MS_CALLBACK file_ctrl(BIO *b, int cmd, long num, void *ptr)
 		b->ptr=(char *)ptr;
 		b->init=1;
 		{
-		int fd = fileno((FILE*)ptr);
 #if defined(OPENSSL_SYS_WINDOWS)
+		int fd = fileno((FILE*)ptr);
 		if (num & BIO_FP_TEXT)
 			_setmode(fd,_O_TEXT);
 		else
 			_setmode(fd,_O_BINARY);
 #elif defined(OPENSSL_SYS_NETWARE) && defined(NETWARE_CLIB)
+		int fd = fileno((FILE*)ptr);
          /* Under CLib there are differences in file modes
          */
 		if (num & BIO_FP_TEXT)
@@ -228,6 +229,7 @@ static long MS_CALLBACK file_ctrl(BIO *b, int cmd, long num, void *ptr)
 		else
 			_setmode(fd,O_BINARY);
 #elif defined(OPENSSL_SYS_MSDOS)
+		int fd = fileno((FILE*)ptr);
 		/* Set correct text/binary mode */
 		if (num & BIO_FP_TEXT)
 			_setmode(fd,_O_TEXT);
@@ -243,6 +245,7 @@ static long MS_CALLBACK file_ctrl(BIO *b, int cmd, long num, void *ptr)
 				_setmode(fd,_O_BINARY);
 			}
 #elif defined(OPENSSL_SYS_OS2)
+		int fd = fileno((FILE*)ptr);
 		if (num & BIO_FP_TEXT)
 			setmode(fd, O_TEXT);
 		else