If execute ./scripts/documentation-file-ref-check in a directory which is
not a git tree, it will exit without a line break, fix it.

Without this patch:

[loongson@localhost linux-5.7-rc1]$ ./scripts/documentation-file-ref-check
Warning: can't check if file exists, as this is not a git tree[loongson@localhost linux-5.7-rc1]$

With this patch:

[loongson@localhost linux-5.7-rc1]$ ./scripts/documentation-file-ref-check
Warning: can't check if file exists, as this is not a git tree
[loongson@localhost linux-5.7-rc1]$

Signed-off-by: Tiezhu Yang <[email protected]>
Reviewed-by: Mauro Carvalho Chehab <[email protected]>
Link: https://lore.kernel.org/r/[email protected]


Signed-off-by: Jonathan Corbet <[email protected]>