Don't require R10 to be read-only

Leave it up to the verifier

Signed-off-by: Dave Thaler <[email protected]>

isa/kernel.org/instruction-set.rst

@@ -30,7 +30,7 @@ The eBPF calling convention is defined as:
 * R0: return value from function calls, and exit value for eBPF programs
 * R1 - R5: arguments for function calls
 * R6 - R9: callee saved registers that function calls will preserve
-* R10: read-only frame pointer to access stack
+* R10: frame pointer to access stack
 
 Registers R0 - R5 are scratch registers, meaning the BPF program needs to either
 spill them to the BPF stack or move them to callee saved registers if these