mon/OSDMonitor.cc: fix UNINTENDED_INTEGER_DIVISION

mon/OSDMonitor.cc: fix UNINTENDED_INTEGER_DIVISION

Fix for:

CID 1297885 (#1 of 2): Result is not floating-point (UNINTENDED_INTEGER_DIVISION)
 integer_division: Dividing integer expressions g_conf->mon_pool_quota_warn_threshold
 and 100, and then converting the integer quotient to type float. Any remainder,
 or fractional part of the quotient, is ignored.

CID 1297885 (#2 of 2): Result is not floating-point (UNINTENDED_INTEGER_DIVISION)
 integer_division: Dividing integer expressions g_conf->mon_pool_quota_crit_threshold
 and 100, and then converting the integer quotient to type float. Any remainder,
  or fractional part of the quotient, is ignored.

Signed-off-by: Danny Al-Gaaf <danny.al-gaaf@bisect.de>