sview - fix SIGABRT when incorrectly freeing global_edit_error_msg.

Bug was introduced in 22c9e25c. Stack trace:

Thread 1 (Thread 0x7ff64228c300 (LWP 6652)):
../sysdeps/unix/sysv/linux/raise.c:58
fmt=fmt@entry=0x7ff6409bb000 "*** Error in `%s': %s: 0x%s ***\n") at
../sysdeps/posix/libc_fatal.c:175
ptr=<optimized out>, str=0x7ff6409bb110 "double free or corruption (out)",
 action=3) at malloc.c:5048
 have_lock=<optimized out>) at malloc.c:3904
 malloc.c:2984
 new_text=0x561a4f8b4d10 "asfasdf", column=21) at
 ../../../../slurm/src/sview/resv_info.c:331
 event=0x561a4f8a8f10, resv_msg=0x561a4f8b1410) at
 ../../../../slurm/src/sview/resv_info.c:515

Bug 2329