Bug fix in commit for printing the function return value for non-trivial values

Bug fix in commit for printing the function return value for non-trivial values

The recent commit:

  commit a0eda3df5b750ae32576a9be092b361281a41787
  Author: Carl Love <cel@us.ibm.com>
  Date:   Mon Nov 14 16:22:37 2022 -0500

    PowerPC, fix support for printing the function return value for non-trivial values.

Is generating a segmentation fault on x86_64-linux.

  segfault:
  ...
  PASS: gdb.asm/asm-source.exp: info source asmsrc1.s
  ERROR: GDB process no longer exists
  UNRESOLVED: gdb.asm/asm-source.exp: finish from foo3
  ...

  Reproduced on command line:
  ...
  $ gdb -q -batch -x outputs/gdb.asm/asm-source/gdb.in.1
  ...

  The problem seems to be that:
  ...
  Thread 1 "gdb" received signal SIGSEGV, Segmentation fault.
  0x000000000043de7a in symbol::type (this=0x0) at
  .../gdb_versions/devel/src/gdb/symtab.h:1287
  1287        return m_type;
  ...
  because:
  ...
  (gdb) up
  #1  0x0000000000852d94 in finish_command (arg=0x0, from_tty=0)
     at .../gdb_versions/devel/src/gdb/infcmd.c:1887
  1887        = check_typedef (sm->function->type ()->target_type ());
  (gdb) p sm->function
  $1 = (symbol *) 0x0

The code is not checking if sm->function is NULL.  If sm->function is NULL
the check for the return buffer should be skipped.