plugins/shannon: Fix shannon-nvme.c linux kernel check patch errors and warnings

plugins/shannon: Fix shannon-nvme.c linux kernel check patch errors and warnings

Note: Still the remaining warning messages are not fixed as same with nvme.c.

WARNING: quoted string split across lines
+       const char *desc = "Read operating parameters of the "
+               "specified controller. Operating parameters are grouped "

...

WARNING: quoted string split across lines
+               "are vendor-specific and not changeable. Use set-feature to "
+               "change saveable Features.\n\n"

WARNING: quoted string split across lines
+       const char *desc = "Modify the saveable or changeable "
+               "current operating parameters of the controller. Operating "

...

WARNING: quoted string split across lines
+               "Use get-feature to determine which Features are supported by "
+               "the controller and are saveable/changeable.\n\n"

total: 0 errors, 16 warnings, 381 lines checked

Signed-off-by: Tokunori Ikegami <ikegami.t@gmail.com>