Documentation: vmcoreinfo: Fix htmldocs warning
Since commit
2369f171d5c5 ("arm64: crash_core: Export MODULES, VMALLOC,
and VMEMMAP ranges"), Stephen reports a warning when building htmldocs:
| Documentation/admin-guide/kdump/vmcoreinfo.rst:498: WARNING: Title underline too short.
Extend the underline to squash the warning.
Fixes:
2369f171d5c5 ("arm64: crash_core: Export MODULES, VMALLOC, and VMEMMAP ranges")
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Will Deacon <will@kernel.org>