utils: handle missing file in getlinuxversion function

The function getlinuxversion receives a path to the os-release
file. The case of not being able to open it was not handled and
thus causing an unwanted exception.

src/utils/probe.py

@@ -9,6 +9,7 @@
 import os
 import subprocess
 import platform
+import logging
 
 from enum import Enum
 from subprocess import PIPE
@@ -25,17 +26,20 @@ def getlinuxversion(osrelease):
     """
     mountpoint = find_mountpoint(osrelease)
 
-    with open(osrelease, 'r') as f:
-        for line in f:
-            if line.find('=') == -1:
-                continue
-            key, value = line.split('=')
-            if key == 'PRETTY_NAME':
-                value = value.replace('\n', '')
-                value = value.strip('"')
-                bits = ' 64 bits' if linux_is64bit(mountpoint) else ''
-                return f'{value}{bits}'
-        return 'Linux'
+    try:
+        with open(osrelease, 'r') as f:
+            for line in f:
+                if line.find('=') == -1:
+                    continue
+                key, value = line.split('=')
+                if key == 'PRETTY_NAME':
+                    value = value.replace('\n', '')
+                    value = value.strip('"')
+                    bits = ' 64 bits' if linux_is64bit(mountpoint) else ''
+                    return f'{value}{bits}'
+    except FileNotFoundError as e:
+        logging.error(f'os-release file not found at "{osrelease}"')
+    return 'Linux'
 
 
 def getwindowsversion(winreghives):