Fix gsmart300 camlib compilation warnings.
Fix gsmart300 camlib compilation warnings.

gsmart300.c:
* gsmart300_reset(...): sleep(...) function takes integer argument so avoid implicit casting by changing number to integer.
* gsmart300_download_data(...): Signed-unsigned comparison issue. Variable 'i' is already treated as unsigned in compares and cannot be negative as the buffer offset would cause segfault.
* gsmart300_get_FATs(...): Signed-unsigned comparison issue. The 'index' variable is used in a very simple way and already used as an unsigned integer in compares.

gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2,gphoto/libgphoto2