sensord: convert cpp to C because they are from opensource

the original files of them from open source are based on C not cpp.
so change the language of these files to C language.

Signed-off-by: Kibak Yoon <kibak.yoon@samsung.com>
Change-Id: I8ae5369c8e9d611576c754d7cbb2e4ae6d04dffb

diff --git a/src/fusion_util.cpp b/src/fusion_util.c
similarity index 100%
rename from src/fusion_util.cpp
rename to src/fusion_util.c

diff --git a/src/geomanetic_field.cpp b/src/geomagnetic_field.c
similarity index 100%
rename from src/geomanetic_field.cpp
rename to src/geomagnetic_field.c