BugLink: https://bugs.launchpad.net/bugs/1858462

[ Upstream commit 21915eca ]

build_initial_tok_table() overwrites unused sym_entry to shrink the
table size. Before the entry is overwritten, table[i].sym must be freed
since it is malloc'ed data.

This fixes the 'definitely lost' report from valgrind. I ran valgrind
against x86_64_defconfig of v5.4-rc8 kernel, and here is the summary:

[Before the fix]

  LEAK SUMMARY:
     definitely lost: 53,184 bytes in 2,874 blocks

[After the fix]

  LEAK SUMMARY:
     definitely lost: 0 bytes in 0 blocks
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>