default or selected kernelversion does not have config value CONFIG_FORCED_INLINING.
Result is shown for kernelversion 5.2.15

Force gcc to inline functions marked 'inline'

configname: CONFIG_FORCED_INLINING

Linux Kernel Configuration
└─>Force gcc to inline functions marked 'inline'
In linux kernel since version 2.6.16 (release Date: 2006-03-19)  
This option determines if the kernel forces gcc to inline the functions
developers have marked 'inline'. Doing so takes away freedom from gcc to
do what it thinks is best, which is desirable for the gcc 3.x series of
compilers. The gcc 4.x series have a rewritten inlining algorithm and
disabling this option will generate a smaller kernel there. Hopefully
this algorithm is so good that allowing gcc4 to make the decision can
become the default in the future, until then this option is there to
test gcc for this.