Remove 'egrep' and use 'grep -E' instead.

The command 'egrep' (and 'fgrep') has been deprecated since 2007.
GNU egrep 3.8+ now prints a warning that 'egrep' is deprecated and this
warning appears in the gvm command output.

It has been over 16 years since 'egrep' and 'fgrep' were deprecated and
it's time to stop using them.  Furthermore, POSIX does not even include an
'egrep' or 'fgrep' command, only 'grep'.

scripts/function/gvm_export_path

@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 function gvm_export_path() {
-	export PATH="$GVM_ROOT/bin:$(echo "$PATH" | $TR_PATH ":" "\n" | "$GREP_PATH" -v '^$' | $EGREP_PATH -v "$GVM_ROOT/(pkgsets|gos|bin)" | $TR_PATH "\n" ":" | $SED_PATH 's/:*$//')"
+	export PATH="$GVM_ROOT/bin:$(echo "$PATH" | $TR_PATH ":" "\n" | "$GREP_PATH" -v '^$' | $GREP_PATH -E -v "$GVM_ROOT/(pkgsets|gos|bin)" | $TR_PATH "\n" ":" | $SED_PATH 's/:*$//')"
 	export GVM_PATH_BACKUP="$PATH"
 }
 

scripts/function/tools

@@ -3,7 +3,6 @@ LS_ERROR="GVM couldn't find ls"
 TR_ERROR="GVM couldn't find tr"
 SED_ERROR="GVM couldn't find sed"
 GREP_ERROR="GVM couldn't find grep"
-EGREP_ERROR="GVM couldn't find egrep"
 SORT_ERROR="GVM couldn't find sort"
 HEAD_ERROR="GVM couldn't find head"
 HEXDUMP_ERROR="GVM couldn't find hexdump"
@@ -12,7 +11,6 @@ LS_PATH=$(unalias ls &> /dev/null; command -v ls) || display_error "$LS_ERROR" |
 TR_PATH=$(unalias tr &> /dev/null; command -v tr) || display_error "$TR_ERROR" || return 1
 SED_PATH=$(unalias sed &> /dev/null; command -v sed) || display_error "$SED_ERROR" || return 1
 GREP_PATH=$(unalias grep &> /dev/null; command -v grep) || display_error "$GREP_ERROR" || return 1
-EGREP_PATH=$(unalias egrep &> /dev/null; command -v egrep) || display_error "$EGREP_ERROR" || return 1
 SORT_PATH=$(unalias sort &> /dev/null; command -v sort) || display_error "$SORT_ERROR" || return 1
 HEAD_PATH=$(unalias head &> /dev/null; command -v head) || display_error "$HEAD_ERROR" || return 1
 HEXDUMP_PATH=$(unalias hexdump &> /dev/null; command -v hexdump) || display_error "$HEXDUMP_ERROR" || return 1