Add if(allocated) checks to avoid segfaults

[NickSzapiro-NOAA]

Code currently fills sppt_wts and skeb_wts whether or not associated with a target or allocated in MOM6. This leads to a segmentation fault in a UFS regression test (see ufs-community/ufs-weather-model#2711)

Protect by checking whether allocated first

[pjpegion]

I recommend splitting the if (pert_epbl .OR. do_ocnsppt) then block to be:

allocate(tmp_wts(gis_stochy_ocn%nx, gis_stochy_ocn%ny))
if (pert_epbl ) then
call get_random_pattern_scalar(rpattern_epbl1, nepbl, gis_stochy_ocn, tmp_wts)
t_rp1(:,:) = 2.0 / (1.0 + exp(-1 * tmp_wts))
call get_random_pattern_scalar(rpattern_epbl2, nepbl, gis_stochy_ocn, tmp_wts)
t_rp2(:,:) = 2.0 / (1.0 + exp(-1 * tmp_wts))
endif
if (do_ocnsppt) then
call get_random_pattern_scalar(rpattern_ocnsppt, nocnsppt, gis_stochy_ocn, tmp_wts)
sppt_wts = 2.0 / (1.0 + exp(-1 * tmp_wts))
else
deallocate(tmp_wts)

[NickSzapiro-NOAA]

@pjpegion Is this what you mean, to split the options?

[pjpegion]

This looks good