kernel: reword issues with full /boot partition

Author: Duncaen

src/config/kernel.md

@@ -26,8 +26,9 @@ When updating the kernel, old versions are left behind in case it is necessary
 to roll back to an older version. Over time, old kernel versions can accumulate,
 consuming disk space and increasing the time taken by dkms module updates.
 Furthermore, if `/boot` is a separate partition and fills up with old kernels,
-it can cause a kernel panic. Thus, it may be advisable to clean old kernels from
-time to time.
+updating can fail or result in incomplete initramfs filesystems to be generated
+and result in kernel panics if they are being booted. Thus, it may be advisable
+to clean old kernels from time to time.
 
 Removing old kernels is done using the
 [vkpurge(8)](https://man.voidlinux.org/vkpurge.8) utility. `vkpurge` comes