staging: most: dim2: remove unnecessary NULL check in try_start_dim_transfer()

staging: most: dim2: remove unnecessary NULL check in try_start_dim_transfer()

Remove the !hdm_ch check. Although hdm_ch is a function parameter,
it is already dereferenced on the preceding line to initialize
head (head = &hdm_ch->pending_list), so a NULL check after that
point is dead code.

Reported-by: Dan Carpenter <error27@gmail.com>
Closes: https://lore.kernel.org/all/acwjEHyEYg0V3OyC@stanley.mountain
Signed-off-by: Gabriel Rondon <grondon@gmail.com>
Link: https://patch.msgid.link/20260401101038.24304-1-grondon@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>