riscv: Docs: fix unmatched quote warning

[ Upstream commit 50da1c9 ]

'make htmldocs' complains about ``prctrl` -- so add a second '`' to
avoid the warning.

Documentation/arch/riscv/zicfilp.rst:79: WARNING: Inline literal start-string without end-string. [docutils]

Fixes: 08ee155 ("prctl: cfi: change the branch landing pad prctl()s to be more descriptive")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260406232304.1892528-1-rdunlap@infradead.org
Signed-off-by: Paul Walmsley <pjw@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

Author: rddunlap

Documentation/arch/riscv/zicfilp.rst

@@ -78,7 +78,7 @@ the program.
 
 Per-task indirect branch tracking state can be monitored and
 controlled via the :c:macro:`PR_GET_CFI` and :c:macro:`PR_SET_CFI`
-``prctl()` arguments (respectively), by supplying
+``prctl()`` arguments (respectively), by supplying
 :c:macro:`PR_CFI_BRANCH_LANDING_PADS` as the second argument.  These
 are architecture-agnostic, and will return -EINVAL if the underlying
 functionality is not supported.