gdb: change duplicate test name in gdb.base/jit-so.exp

gdb: change duplicate test name in gdb.base/jit-so.exp

When running gdb.base/jit-so.exp, we see duplicate test names:

$ grep PASS testsuite/gdb.sum | sort | uniq -c | sort -n
      ...
      2 PASS: gdb.base/jit-so.exp: one_jit_test-1: info function jit_function
      2 PASS: gdb.base/jit-so.exp: one_jit_test-2: info function jit_function

Give an explicit name to one test to avoid this.

gdb/testsuite/ChangeLog:

	* gdb.base/jit-so.exp (one_jit_test): Change test name.