scsi: megaraid_sas: Protect more code with instance->reset_mutex

megasas_get_device_list() and megasas_get_snapdump_properties() may unlock
instance->reset_mutex indirectly. Hence, hold reset_mutex while calling
these functions.

Cc: Kashyap Desai <kashyap.desai@broadcom.com>
Cc: Sumit Saxena <sumit.saxena@broadcom.com>
Cc: Shivasharan S <shivasharan.srikanteshwara@broadcom.com>
Cc: Chandrakanth patil <chandrakanth.patil@broadcom.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Martin K. Petersen <martin.petersen@oracle.com>
Cc: megaraidlinux.pdl@broadcom.com
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://patch.msgid.link/20260223220102.2158611-31-bart.vanassche@linux.dev
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>