file.c: fix uninitialized variable

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
libdivecomputer.c: reduce the scope of 'i' in sample_cb()

Silences a warning about an unused variable.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>
configuredivecomputerthreads.cpp: conditionally define read_ostc_cf()

Fixes a warning. The function is only used if
DC_VERSION_CHECK(0, 5, 0) is defined.

Signed-off-by: Lubomir I. Ivanov <neolit123@gmail.com>
Signed-off-by: Dirk Hohndel <dirk@hohndel.org>