Revert "kexec: Export kexec_in_progress to modules"

This reverts commit 97dcaa0fcfd24daa9a36c212c1ad1d5a97759212. Based on
the review discussion with Eric, we will come up with a different fix
for the bcm_sf2 driver which does not make it rely on the
kexec_in_progress value.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

kernel/kexec_core.c

@@ -59,7 +59,6 @@ size_t vmcoreinfo_max_size = sizeof(vmcoreinfo_data);
 
 /* Flag to indicate we are going to kexec a new kernel */
 bool kexec_in_progress = false;
-EXPORT_SYMBOL_GPL(kexec_in_progress);
 
 
 /* Location of the reserved area for the crash kernel */