B #4072: Fix monitoring probes (#4073)

(cherry picked from commit 42df8eb2e3)

src/vmm_mad/remotes/kvm/poll

@@ -166,7 +166,7 @@ module KVM
     end
 
     def self.number_of_processors
-        %x{nproc}.to_i
+        `grep -c processor /proc/cpuinfo`.to_i
     end
 
     def self.get_cpu_jiffies

src/vmm_mad/remotes/lxd/poll

@@ -162,7 +162,7 @@ module LXD
         #   @param vm_names [Array] of vms indexed by name. Value is a hash with :pid
         #   @return  [Hash] with ps information
         def get_cpu(vm_names)
-            multiplier = `nproc`.to_i * 100
+            multiplier = `grep -c processor /proc/cpuinfo`.to_i * 100
 
             start_cpu_jiffies = get_cpu_jiffies