That's the asolute wrong way for build and installing kernels in debian!
Your system does not know any header of that running kernel!
If you think, you need to selfbuild kernels, your should care about how to do that propper!
Kernel upstream has deb-pkg as make target, which you shouöd use, because then you get debian packages for kernel, headers and firmware (and linux-libc-dev which you should ignore) , which can be clean installed with the package manager.