parser: fix DLF import

In bc3b56a969, the import of the dive mode was simplified,
by replacing an if-else-if chain by bit manipulations.
However, the bitmask was wrong: 0b00111000 is 0x38 not 0x30,
which means that "odd" dive modes were not recognized as such.

Bug found by coverity.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

core/parse-xml.c

@@ -1854,7 +1854,7 @@ int parse_dlf_buffer(unsigned char *buffer, size_t size, struct dive_table *tabl
 	// ptr[14] >> 1 is scrubber used in %
 
 	// 3 bit dive type
-	switch((ptr[15] & 0x30) >> 3) {
+	switch((ptr[15] & 0x38) >> 3) {
 	case 0: // unknown
 	case 1:
 		state.cur_dc->divemode = OC;